Method and device for producing metal rings

ABSTRACT

A method and an arrangement for producing rings from a metallic material are provide, wherein the rings are provided with an axially continuous inner profile at an inner circumference, and with a radial outer profile at an outer circumference. The method can include: providing a tube having a tube section from which rings are to be produced; forming an inner profile of the tube section by swaging, wherein a first profile mandrel is arranged in the tube, an outer profile of the mandrel corresponds to the inner profile of the rings to be formed, and the tube section is processed from outside by a swaging tool; and forming a radial outer profile to by rolling.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of International Patent App. No.PCT/EP2006/005695 filed on Jun. 14, 2006, and also claims priority toGerman Patent App. No. 10 2005 028 828.6 filed on Jun. 15, 2005. Theentire contents of both prior-filed patent applications are herebyincorporated herein by reference.

BACKGROUND

The present invention relates to a method and assembly for producingrings from a tube made of a metallic material, wherein the rings areprovided with an axially continuous inner profile at their innercircumference and with a radial outer profile at their outercircumference.

Such a method is, for example, known from DE 102 19 441 C1. The methoddescribed in DE 102 19 441 C1 serves to produce rings that are profiledinside and outside (e.g., rolling bearing rings and transmission rings)from tubular or solid materials, and in a state completely ready forgrinding. A radial outer profile can be formed by radial-axial-profiletube rolling. Therein, a tube section is processed from the outside byusing a rolling tool. The flow of material generated therewith isinfluenced by a counterforce tool which acts on the processed tubesection in an axial direction. The flow of material may be controlled inaxial and radial directions, such that the evading material may beinvolved in formation of the profile.

For manufacturing such products as, for example, synchronizer rings, aradial inner profile may be formed simultaneously. For the production ofshifting sleeves, it is proposed to machine the required inner teeth(i.e., axial profile) in a separate working step after the outer contourhas been rolled completely ready for grinding.

SUMMARY

In view of the above, it is an object of the invention to provide anenhanced method for producing rings from a metallic material, andstarting from a raw material, wherein in particular axial profiles canbe produced with greater ease.

This object is solved by a method for producing rings from a metallicmaterial, wherein the rings are provided with an axially continuousinner profile at an inner circumference and with a radial outer profileat an outer circumference, and wherein the method comprises the steps ofproviding a tube having a tube section from which rings are to beproduced; forming an inner profile of the tube section by swaging,wherein a first profile mandrel is arranged in the tube, the outerprofile of the mandrel corresponds to the inner profile to be formed,and the tube section is processed from the outside by using a swagingtool; and forming a radial outer profile by rolling.

Similarly, the above object is solved by an assembly for producing ringsfrom a metallic material (such as in performing the aforementionedmethod), wherein the assembly comprises: a swaging device for forming aninner profile, wherein the swaging device has a first profile mandrelarranged in the tube and having an outer profile corresponding to theinner profile of rings to be formed, and wherein the swaging deviceincludes a swaging tool which processes the tube section from outside inorder to form a tube section being profiled inside; and a rolling devicefor forming the outer profile.

With the inventive method and the inventive production assembly, theaxial inner profile of the rings can be produced at considerably lowercosts, i.e. by swaging. Since the metallic material used for producingthe rings is capable of flowing to a certain extent due to the rollingmethod used for producing the radial outer profile, the swaging methodfor producing the axial inner profile is generally applicable.

As used herein, the term “swaging” has a broad meaning in this context,and includes all similar and alternative methods in which material ispressed into a profile of the profile mandrel by radial and/or axialpressure (e.g., intermittently, in some embodiments).

The axial inner profile produced in the manner described herein issurprisingly not influenced or is only slightly influenced in thesubsequent rolling step for producing the radial outer profile, suchthat, in some cases, post-processing of the axial inner profile afterthe rolling step is not required.

The rings produced in the manners described and illustrated herein mayin particular be shifting sleeves or clutch bodies, such as those usedin transmissions.

In an alternative embodiment of the production method, the individualrings can be separated from the internally profiled tube section beforethe rolling step described above.

In this embodiment, it is preferred that, in the rolling step, the flowof material is controlled possibly from both axial sides near therolling tool.

In an alternative embodiment, the rolling step described above isperformed at the internally profiled tube section, wherein the finishedrings are subsequently cut off.

Handling of the worked product is advantageous in this context, since alarge number of single parts is not generated until the rings arefinished.

Furthermore, it is advantageous if the tube is moved in an axialdirection with respect to the swaging tool in the swaging step describedabove.

In this embodiment, the axial inner profile may be formed in acontinuous working step upon the tube section. As an alternative, it ispossible to move the swaging tool with respect to the tube.

It is also advantageous in some embodiments if the outer profile of thefirst profile mandrel is shorter than the length of the tube section,wherein the first profile mandrel is supported in a floating fashion,and wherein the tube section is moved in the axial direction withrespect to the first profile mandrel in the swaging step.

With such embodiments, the length of the tube section at which the axialinner profile is formed in one piece can be configured comparativelylong, such as 50 to 70 cm (20 to 28 in). However, it is also possible toform the tube section even longer, such as 2 m (6.6 ft) or more.

Compared to other methods, the utilizable portion of the basic tube canbe considerably enlarged, since the length of the profiled tube sectionin relation to the length of the normally required clamping of the tubebecomes larger.

Furthermore, it is advantageous in some embodiments that the firstprofile mandrel is supported in an axial direction in the swaging step,and remains substantially stationary with respect to the swaging tool.

In some embodiments, the profile mandrel is supported in a floatingmanner. However, in order to avoid deadlocks, a support in the axialdirection may be provided, such as in the direction of movement of thetube section with respect to the first profile mandrel.

Also, in some embodiments, it is particularly advantageous if a secondprofile mandrel is arranged in the tube section or ring in the rollingstep described above.

By arranging the second profile mandrel (as just described), the outerprofile of which corresponds to the already finished axial inner profileof the tube section or ring, the rolling step may be performed such thata flow of material does not affect the integrity of the already finishedinner profile.

Although it may possibly be necessary to perform post-processing of theaxial inner profile after the rolling step, in some embodiments, nofurther post-processing is required at all, or at least nopost-processing by machining is required.

In some embodiments of the production method, an axial counterforceacting on the tube section or the ring is generated in the rolling step(e.g., opposite to the direction of flow of the material caused by therolling tools) in order to be able to control the flow of material inaxial and/or radial directions.

In such embodiments, it radial elevations can be produced during therolling of the radial outer profile, wherein the elevations exceed theouter diameter of the non-rolled tube. In other words, a radiallyoutward flow of material can be generated in order to form a radialouter profile having comparatively large differences between maximum andminimum outer diameters while affecting the already finished axial innerprofiles as little as possible.

Even if the aforementioned production method in which the first profilemandrel is shorter than the tube section to be axially profiled ispreferred, it is also possible, according to some embodiments of thepresent invention, that the outer profile of the first profile mandrelis approximately or at least as long as the tube section, wherein thefirst profile mandrel moves in an axial direction together with the tubeor with respect to the swaging tool in the swaging step.

With such embodiments, the axial inner profile is formed from outside byswaging tools by generating a flow of material into the radial outerprofile of the profile mandrel. In these embodiments, however, norelative speed between the profile mandrel and the tube section exists,such that production accuracy can be very high.

In the embodiments described herein in which the profile mandrel issupported in a floating manner, it is possible that the shape of theradial inner profile changes slightly after the swaging at the profilemandrel, in particular if the infeed speed is not optimally adjusted.

In some embodiments of the production assembly, the outer profile of thefirst profile mandrel is shorter than the length of the tube section,wherein the first profile mandrel is supported in a floating manner withrespect to the tube.

In the rolling device, a counterforce tool can be used, wherein thecounterforce tool includes an abutting section with which an axialcounterforce acting on the tube section or the ring can be generatedopposite to the direction of the flow of material caused by the rollingtools, in order to control the flow of material in axial and/or radialdirections.

The counterforce tool can be formed integrally with the second profilemandrel, in some embodiments.

In some embodiments of the inventive production assembly, a separatingdevice for separating individual rings from the tube section can beutilized.

For this purpose, a separate device can be used, such as a turning tool,a milling tool, a grinding tool, a saw, and the like, for radiallycutting off individual tubes.

The separating device can be arranged in front of the rolling device inorder to supply individual rings profiled only at their innercircumference to the rolling device.

As an alternative, the separating device can be arranged at or behindthe rolling device in order to cut off individual rings from the tubesection, wherein each ring is already profiled at its innercircumference as well as at its outer circumference.

The aforementioned features and the features explained below can be usedin any combination or alone without leaving the scope of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are shown in the drawings and explained indetail in the following description.

FIG. 1 shows a cylindrical tube made of a metallic material, which issuitable as a basic workpiece for the production method of theinvention;

FIG. 2 is a schematic longitudinal sectional view of a swaging device ofa production assembly according to an embodiment of the presentinvention;

FIG. 3 shows a perspective view of a tube section with axial innerprofile produced in the swaging device of FIG. 2;

FIG. 4 is a schematic longitudinal sectional view of a rolling device ofa production assembly according to an embodiment of the presentinvention;

FIG. 5 is a schematic longitudinal sectional view of an alternativeembodiment of a rolling device of a production assembly according to anembodiment of the present invention;

FIG. 6 is a schematic longitudinal sectional view of an alternativeembodiment of a swaging device for a production assembly according to anembodiment of the present invention;

FIG. 7 is a plan view of a clutch body produced according to anembodiment of the present invention; and

FIG. 8 is a sectional view along line VIII-VIII of FIG. 7.

DETAILED DESCRIPTION

In FIG. 1, a cylindrical tube as a basic workpiece for the productionmethod according to some embodiments of the present invention isgenerally designated with reference numeral 10. The basic tube 10 isnon-profiled at its inner circumference as well as at its outercircumference, and is made of a metallic material suitable for beingprocessed in a swaging device and a rolling device. The metallicmaterial is in any case capable of flowing to a certain extent. In someembodiments, the material can be heated during processing.

According to the production method according to some embodiments of thepresent invention, the tube 10 will be reshaped into a plurality ofrings each having an axial inner profile at an inner circumference and aradial outer profile at an outer circumference, such as for shiftingsleeves for transmissions.

FIG. 2 shows a schematic longitudinal sectional view of a swaging device12 in a production assembly according to an embodiment of the presentinvention.

The swaging device 12 comprises a swaging tool 14 with swaging jaws 16acting from radially outside of the tube 10 in a manner generally knownto those skilled in the art.

The swaging device 12 is used to generate an axial inner profile of thebasic tube 10, such as a toothed inner profile.

For this purpose, a first profile mandrel 20 is supported in the swagingdevice 12.

The profile mandrel 20 comprises a section being comparably short in anaxial direction, wherein the section includes an outer profile 22 of themandrel 20. The outer profile 22 has a shape corresponding to the innerprofile which is to be generated in the tube 10.

Further, the profile mandrel 20 shown in FIG. 2 comprises a conicalsection 24 arranged in an axial feed direction 26 in front of the outerprofile 22 of the mandrel 20.

During the swaging process, a certain reduction of the diameter of thebasic tube 10 occurs, and the axial front end of the conical section 24is conformed to the inner circumference of the basic tube 10, whereasthe rear end of the conical section is conformed to the reduced diameterof the outer profile 22 of the mandrel 20.

The profile mandrel 20 illustrated in FIG. 2 is supported afloat withinthe tube 10 (i.e., it remains substantially stationary with respect tothe swaging tool 14). The tube 10 is inserted in the axial direction 26with respect to the swaging device 12. The profiling of the innercircumference of the tube 10 is performed within the swaging tool 14.Herein, the profile mandrel 20 may be supported in the axial directionby an optional supporting device 27, in particular for avoidingdeadlocks and the like.

In the swaging device 12, a tube section 28 of the tube 10 is providedwith the axial inner profile, wherein the tube section 28 isconsiderably longer than the outer profile 22 of the mandrel 20. Forexample, the tube section 28 may have a length of 50 or 60 cm (20 to 25in), and can even have a length of 2 m (6.6 ft) or more. In someembodiments, the tube section 28 can be indefinitely long.

Using the process described above, a major part (i.e., tube section 28)of the basic tube 10 can be profiled. In some embodiments, generally noprofiling or a non-usable profiling is generated at either or both endsof the tube 10, due to a bearing point.

FIG. 3 shows a tube section 30 produced in the swaging device 12,wherein the tube section 30 is provided with an axial inner profile 32.

The internally profiled tube section 30 may now be supplied to a rollingdevice for producing a radial outer profile. As an alternative, it isalso possible to separate individual internally profiled rings 36 fromthe internally profiled tube section 30, such as by a separating device34, as shown schematically in FIG. 3. The separation may be performed,for example, by cut-off turning or in any other suitable manner.

FIG. 4 shows a schematic longitudinal sectional view of a rolling device40 of a production assembly according to an embodiment of the presentinvention.

The rolling device 40 is arranged downstream of the swaging device 12.In the rolling device 40, an internally profiled tube section 30 is usedas a basic workpiece. At the internally profiled tube 30, a radial outerprofile of a ring to be produced is rolled, wherein the thus finishedring is subsequently separated from the internally profiled tube 30,such as by a separating device 34 a, which is also schematically shownin FIG. 4.

Subsequently, a further section of the internally profiled tube section30 may be rolled in order to produce a further ring, which is then againseparated.

The rolling device 40 can be structured and operated as described indocument DE 102 19 441 C1, the entire contents of which are incorporatedherein by reference.

The rolling device 40 shown in FIG. 4 comprises at least two rollers 42which are rotatable in a rolling motion 44 about axes, wherein the axesextend parallel to the longitudinal axis of the clamped tube section 30.

Further, the rollers 42 respectively apply a radial pressure onto thetube section 30, as is schematically indicated at reference numeral 44.

One end of the tube section 30 is clamped by means of a chuck 46, and isrotated about its longitudinal axis via the chuck 46, as isschematically shown at reference numeral 48.

However, a difference vis-à-vis DE 102 19 441 C1 is that the tubesection 30 has an axial inner profile 32 which shall be affected aslittle as possible, and in some cases to no extent or substantially noextent, during the rolling process.

For this purpose, a second profile mandrel 50 is provided in the rollingdevice 40. The second profile mandrel 40 has a first section with anouter profile 52 which corresponds to the axial inner profile of thetube section 30.

Further, the second profile mandrel 50 comprises an abutting section 54,the diameter of which is larger than that of the outer profile 52. Theabutting section 54 abuts the free end of the tube section 30 in theaxial direction. The profile mandrel 50 is also movable in the axialdirection, as is schematically indicated at reference numeral 56.Therefore, the second profile mandrel 50 can simultaneously define acounterforce tool, and can be configured to apply an axial force ontothe rolled section. The axial force is adapted to control the flow ofmaterial (namely in the axial direction as is shown at reference numeral58, and in the radial direction as is shown at reference numeral 59).

Consequently, a radial outer profile 62 is produced in the rollingdevice 40 by the rolling processing of a section of the internallyprofiled tube section 30 (namely, the radial outer profile for one ring,or alternatively simultaneously for a plurality of rings). After therolling process, the ring 60 thus finished is separated, such as by theschematically shown separating device 34 a.

By applying an axial pressure onto the tube section 30 during therolling process, the flow of material may be controlled in the axialand/or radial directions, wherein a radial outer profile 62 can finallybe generated, the outer circumference of which can be in sections largerthan the outer circumference of the internally profiled tube section 30.

In the embodiment shown in FIGS. 1-4, the ring 60 being profiled axiallyat its inner circumference and radially at its outer circumference canbe used, for example, as a shifting sleeve for a vehicular transmission.

FIG. 5 shows an alternative embodiment of a rolling device 40′.

The structure and function of the rolling device 40′ correspond to thoseof the rolling device 40 of FIG. 4. The only difference between theillustrated embodiment of FIG. 5 and that of FIG. 4 is that the rollingdevice 40′ shown in FIG. 5 is configured to roll internally profiledrings 36 which have been separated from an internally profiled tubesection 30 in advance (see dotted lines in FIG. 3).

On the side of the ring opposing the abutting section 54′, a furthercounterforce tool 66 may be provided, and can be axially movable as isshown at reference numeral 68. In this manner, the ring may beinfluenced from both sides to control the flow of material.

FIG. 6 shows an alternative embodiment of a swaging device 12′ forproducing an internally profiled tube section 30′.

The structure and function of the swaging device 12′ correspond to thoseof the swaging device 12 of FIG. 2. In the following description, onlythe differences between the swaging device 12′ shown in FIG. 6 and theswaging device 12 shown in FIG. 2 are discussed.

In the swaging device 12′ of FIG. 6, the first profile mandrel 20′comprises a section having an outer profile 22′, the length of whichcorresponds to the tube section 30′ to be formed.

Herein, the first profile mandrel 20′ is clamped in a chuck 70 which isfed to the swaging device 14′ in an axial direction together with thetube 10.

Consequently, a tube section 30′ having an axial inner profile is swagedin the swaging device 12′, wherein the length of the tube sectionapproximately corresponds to the length of the outer profile 22′ of thefirst profile mandrel 20′.

It is discernible that in this case, compared to the method includingthe floating first profile mandrel 20 (shown in FIG. 2), a certainportion of the basic tube 10 (i.e., at the ends thereof) is notutilisable, and can be separated before the tube section 30 is furtherprocessed.

In FIGS. 7 and 8, a clutch body 80 produced according to an embodimentof the method disclosed herein is shown.

According to some embodiments of the present invention, the clutch body80 is provided with an axial inner profile 32″ and a radial outerprofile 62″. The axial inner profile 32″ serves to slide the body onto arespective toothed element or structure, such as a freewheel of atransmission. The radial outer profile 62″ is configured such that theclutch body 80 is readily attachable to a freewheel, such as by welding.Therefore, the radial outer profile 62″ comprises a radial flangesection.

Furthermore, an outer toothed section 82 is provided on the clutch body80, and comprises outer teeth into which the inner teeth of the shiftingsleeve may be inserted in order to obtain a form fit between the clutchbody 80 (and therefore the freewheel connected to the clutch body 80)and a transmission shaft, at which the shifting sleeve is supported tobe axially movable, but stationary.

1. A method for producing rings from a metallic material, the rings provided with an axially continuous inner profile at their inner circumference and with a radial outer profile at their outer circumference, wherein the method comprises the steps of: providing a tube including a tube section from which rings are to be produced; forming the inner profile of the tube section by swaging, wherein a first profile mandrel is arranged in the tube, the first profile mandrel having an outer profile corresponding to the inner profile to be formed, and wherein the tube section is processed from outside by a swaging tool; and forming the radial outer profile of at least one ring by rolling.
 2. The production method of claim 1, wherein individual rings are separated from an internally profiled tube section prior to the forming the radial outer profile.
 3. The production method of claim 1, wherein forming the radial outer profile by rolling is performed at an internally profiled tube section, the method further comprising separating rings from the tube section.
 4. The production method of claim 1, wherein the tube is moved in an axial direction with respect to the swaging tool while the inner profile of the tube section is formed.
 5. The production method of claim 2, wherein the tube is moved in an axial direction with respect to the swaging tool while the inner profile of the tube section is formed.
 6. The production method of claim 3, wherein the tube is moved in an axial direction with respect to the swaging tool while the inner profile of the tube section is formed.
 7. The production method of claim 1, wherein the outer profile of the first profile mandrel is shorter than the length of the tube section, wherein the first profile mandrel is supported afloat, and wherein the tube section is moved in an axial direction with respect to the first profile mandrel while the inner profile of the tube section is formed.
 8. The production method of claim 1, wherein the first profile mandrel is supported in an axial direction while the inner profile of the tube section is formed, and remains substantially stationary with respect to the swaging tool.
 9. The production method of claim 1, wherein a second profile mandrel is arranged in the tube section or the ring, respectively, while the radial outer profile is formed.
 10. The production method of claim 1, wherein an axial counterforce acting on the tube section or the ring is generated opposite to a direction of flow of material, in order to control a flow of material in at least one of an axial and radial direction.
 11. The production method of claim 1, wherein the outer profile of the first profile mandrel is approximately as long as the tube section, and wherein the first profile mandrel is moved in an axial direction together with the tube while the inner profile of the tube section is formed.
 12. An assembly for producing rings from a tube comprising metallic material, the rings being provided with an axially continuous inner profile at their inner circumference and with a radial outer profile at their outer circumference, the assembly comprising: a swaging device for forming the inner profile, wherein the swaging device has a first profile mandrel adapted to be received within a tube section of the tube, the first profile mandrel having an outer profile corresponding to the inner profile of the rings to be formed, the swaging device comprising a swaging tool adapted to process the tube section from outside of the tube in order to form the tube section with an interior profile; and a rolling device for forming the outer profile subsequent to the inner profile.
 13. The production assembly of claim 12, wherein the outer profile of the first profile mandrel is shorter than the length of the tube section, and wherein the first profile mandrel is supported afloat with respect to the tube.
 14. The production assembly of claim 12, wherein the rolling device includes a second profile mandrel, the second profile mandrel having an outer profile corresponding to the inner profile of the tube section, the second profile mandrel adapted to be inserted into the internally profiled tube section or ring in formation of the outer profile of the tube.
 15. The production assembly of claim 13, wherein the rolling device includes a second profile mandrel, the second profile mandrel having an outer profile corresponding to the inner profile of the tube section, the second profile mandrel adapted to be inserted into the internally profiled tube section or ring in formation of the outer profile of the tube.
 16. The production assembly of claim 14, wherein the second profile mandrel is formed as an axially displaceable counterforce tool comprising an abutting section with which an axial counterforce acting on the tube section or the ring is generated opposite the direction of flow of material in order to control a flow of material in at least one of an axial direction and a radial direction.
 17. The production assembly of claim 12, further comprising a separating device for separating individual rings from the tube section.
 18. The production assembly of claim 13, further comprising a separating device for separating individual rings from the tube section.
 19. The production assembly of claim 18, wherein the separating device is arranged in front of the rolling device.
 20. The production assembly of claim 18, wherein the separating device is arranged at or behind the rolling device. 